New digital maps showing storm-based flood potential for the DC area have been added to the National Weather Service’s Advanced Hydrologic Prediction Service. These maps help users visualize when and where various stages of flooding could impact roads, infrastructure, and resources in communities along the Potomac River and four tributaries: the Anacostia River, Cameron Run, Oxon Run, and Four Mile Run.

This is the first interactive flood inundation mapping (FIM) tool for this region. It uses U.S. Army Corps of Engineers’ (Corps) modeling and mapping, and is tied directly to U.S. Geological Survey (USGS) and National Oceanic & Atmospheric Administration (NOAA) water gauges for real-time monitoring of data and will help government leaders, emergency managers, and the public make emergency-response decisions to protect lives and properties in flood zones.

The District will use the FIM as part of a comprehensive, risk-analysis initiative to prepare for possible flood events and inform flood-mitigation strategy and emergency-management plans and operations. Flood depths will be used to estimate physical, economic, and social impacts, including future risk attributed to sea-level rise.

The FIM tool for the Potomac and Anacostia rivers is a project of the DC Silver Jackets, with funding from DOEE and the City of Alexandria. The DC Silver Jackets is an interagency team that leverages resources to identify and implement comprehensive, resilient, and sustainable solutions to reduce flood risks around Washington. It is led jointly by DOEE; the Corps, Baltimore District; and the National Park Service. Other FIM project partners include the Federal Emergency Management Agency, District of Columbia Homeland Security and Emergency Management Agency, and National Capital Planning Commission.

How it works

The National Weather Service issues Potomac and Anacostia Rivers flood predictions based on readings from the Wisconsin Avenue, SW Waterfront, and City of Alexandria water gauges; expected rainfall upstream; and expected storm surge downstream. Based on this forecast and the Corps’ models, you can view a map that projects when and where flooding could occur and how severe it may be. There are more than 30 maps for each gauge.